Furnace structure



Aug. 19, 1958 J. KNIVETON FURNACE smucwuaa:

2 Sheets-Sheet 1 Filed Oct. 14, 1954 JAMES KNIVETON ATTORNEY.

United States FURNACE STRUCTURE Application October 14, 1954, Serial No. 462,175

2 Claims. (Cl. 263-6) The present invention relates to furnaces, and more particularly to a furnace in which the floor or hearth is so mounted that it can expand and contact freely and can readily be removed for repairs.

In many furnaces, especially furnaces of the walking beam type where the work is placed directly upon the floor, the service requirements have been such that the floor is subject to severe strains and wear. Because of the manner in which these furnaces have been constructed, it has been both diflicult and expensive to repair them.

The furnace of the present invention is so constructed that the floor is mounted independently of its supporting structure, so that it is free to expand and contract in response to temperature changes along its length. The construction used is also such that the floor can be removed for necessary repairs without disturbing any of the remaining structure.

It is an object of the invention to provide a furnace in which the floor is easily removable for maintenance and repair. It is a further, and more specific, object of the invention to provide a walking beam type of furnace in which the floor is so mounted on the walking beam mechanism that it is free to expand and contract relative thereto. A separable connection is provided between the floor and its moving mechanism, so that the former can be removed without disturbing the latter.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

In the drawings:

Figure 1 is a side view, partly in section, taken on line 1-1 of Figure 2 showing the furnace of the invention, and

Figure 2 is a view taken on line 2--2 of Figure 1.

Referring to the drawings, it will be seen that the furnace is built in a structural steel framework which includes buckstays 1 from which extend gusset plates 2 that support the side walls 3 of the furnace. These side walls are constructed of refractory material in accordance with the usual furnace practice and include portions that extend inwardly at the bottom toward the center of the furnace and terminate in curbs 4 upon which the work to be heated is intermittently supported. The work is shown herein by way of example as being in the form of rods that are heated for some hot metal working operation. The roof of the furnace can be constructed as an integral part of the walls in the usual arch shape, if it is desired, but is shown herein as being a separate structure which can be removed for inspection and repair. To this end, the roof 5 is provided with a metal frame 6, the outer edges of which rest on horizontally extending flanges 7 of supporting members that are fastened suitably in the side walls and to the buckstays 1. When the roof is atenr placed in position, the spaces between the side walls and the roof will be filled with a suitable refractory cement 8.

A floor 9 extends the length of the furnace between curbs 4. The floor is constructed of suitable refractory material on a backing plate 11 that is, in turn, reinforced by girders 12 running the full length of the furnace. At spaced points along these girders 12, there are provided bearings 13 for the axles 14 of rollers 15 which support the floor. In order to prevent a draft from entering the furnace, between the floor 9 and the curbs 4, there is provided a pair of seals that are formed by angle members 16 attached to the outside of girders 12 and elongated skirts 17 that extend downwardly from the lower portion of the side walls 3. The channels formed by the angle members 16 are filled with a suitable sealing material whimh may be oil or sand. These members 16 and skirts 17 are of a size suflicient to permit the seal to remain effective when movement is imparted to the floor in a manner now to be described.

The floor is given vertical and horizontal movements by a frame 19 upon which it is mounted. The frame includes beams 20, extending the length of the furnace, which are joined by suitable crosspieces 21 upon which tracks 22 are mounted. The rollers 15 on the furnace floor ride along these tracks for a purpose to be described.

The frame 19 is supported and given vertical movements by means of rollers 23 on each side of the frame which engage bearing plates 24 that are attached to the bottom of the beams 20. Rollers 23 are on the outer ends of levers 25 that are attached to shafts 26 mounted for oscillation in bearings 27. Also attached to the shafts 26 are levers 28 each of which, with the levers 25, forms in effect a bell-crank lever. The outer ends of levers 28 on each side of the furnace are connected by links 29, each of which has its right end fastened to the outer end of a lever 30 that is attached to a shaft 32. This shaft is journaled for oscillation in bearings 33 suitably mounted on the frame of the apparatus. Shaft 32 is oscillated by means of engagement between a roller 35 on the outer end of the lever 34, fastened thereto, and a cam 36 which is attached to a shaft 37 that is rotated by a motor, not shown.

Horizontal movement of the frame 19 is obtained in one direction by means of a weight, and in the opposite direction by means of a cam and lever system. To this end, the frame is moved to the left by a weight 38 which is connected through a cable 39 with a lug 41 on the bottom of the frame 19. This cable passes over a pulley 42, so that force is exerted at all times to bias the frame to the left. Movement of the frame to the right is accomplished by a cam 43 on shaft 37 which acts on a roller 44 to oscillate a lever 45, around a pivot formed by a bearing 46 suitably attached to the frame. Movement of the outer end of lever 45 acts through a link 47, extending between the lever and the frame, to reciprocate the frame 19. Movement of the frame is imparted to floor 9 by means of a connection between them consisting of a bar 48 that is hinged at its lower end to the frame at 49, and which is bolted to the end of the floor as shown at 51. Alignment is maintained between the floor and frame 19 by flanges on rollers 15 and between the frame and its supporting and moving mechanism by flanges on rollers 23.

A suitable door 52 is provided at the charge end of the furnace to close as much of the opening thereof as is not needed by the size of the work being heated. The door can be raised or lowered as necessary. To this end, the door is supported by a cable 53 passing over a pulley 54, the other end of the cable being counterweighted in a suitable manner.

As shown in Figure 1, the portion of the side walls including curbs 4 and the floor 9 extend to the right beyond that portion of the furnace forming the heating chamber. These extensions form a loading zone upon which the rods to be heated may be placed for introduction into the furnace.

- In the operation of the furnace, the shaft 37 is driven at a suitable speed to impart alternate vertical and horizontal movements to the frame 19 and floor carried thereby. The cams 36 and 43 are so shaped that the floor will be moved in sequence upwardly, to the left, downwardly and to the right in the conventional manner in which floors are moved in walking beam type furnaces. As shown in the drawings, the floor is in its lower right hand position. Further rotation of the cams will cause the floor to be moved vertically upward, so that outer edges of floor 9 will lift the rods from curbs 4. The floor will then be moved to the left to move these rods toward the discharge end of the furnace. The floor will then be lowered and moved back to the right in order to repeat the operation. Thus, the work is moved intermittently through the furnace which is heated by suitable burners. The rate of movement of the floor, the temperature of the furnace and the length thereof are so computed that the temperature of the work will be brought to the desired value by the time it is discharged down the incline at the left end of the furnace.

From the construction described above, it will be seen that the floor is connected at one point with the frame, this point being through the bar 48. The floor is, therefore, moved along with the frame, but the floor is permitted, because of the rollers 15, to expand and contract due to changes in temperature or for other reasons independently of the walking beam mechanism itself. This means that the walking beam mechanism can be built much more accurately than would otherwise be possible if provision had to be made for expansion and contraction of the floor. It will also be seen that by loosening the bolts 51, the entire floor can be removed through either end of the furnace for inspection and repair. -When the floor is removed, access is also obtained to the side walls and to the curbs 4. This construction has the advantage that the floor which receives the greatest amount of wear in a furnace of this type can be readily removed for inspection and repair without disturbing the mechanism that serves to move this floor when the furnace is in operation. While the floor is shown as being attached to its supporting frame at the discharge end, it will be ap- 4 parent that this connection can be made at any other single point along the length of the floor as desired.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of embodiment of my invention now known to me it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of the invention as set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

1. In a furnace, the combination of mechanism including a horizontal frame, said mechanism including means to move said frame in a vertical direction and means to move said frame in a horizontal direction, an elongated furnace floor subject to changes in length due to changes in furnace temperature, said floor being mounted on said frame, means between said floor and frame operative to permit relative longitudinal movement between the two, a connection between said frame and one point on said floor whereby the remainder of said floor, upon expansion and contraction thereof, may move relative to said frame, and structure forming furnace side walls and roof above said floor and separate therefrom.

2. In a furnace, the combination of structure forming elongated side walls and a roof, a floor adapted to fill the space between the lower portions of the side walls and separate therefrom, mechanism to support said floor, means to give said mechanism limited horizontal movement, means to give said mechanism limited vertical movement, and means to attach said floor to said mechanism including a fastening device extending between said floor and mechanism at one point along the length of said door to prevent relative movement of the floor and mechanism at that point, and means between said floor and mechanism at other points thereof operative to permit relative longitudinal movement therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 1,747,067 Gates Feb. 11, 1930 1,792,074 Cochran Feb. 10, 1931 1,824,742 Larsen Sept. 22, 1931 2,017,024 Cochran et a1. Oct. 8, 1935 2,057,367 Cone Oct. 13, 1936 

